South Korea plans to finalize its decision to expand its air defense zone this week and will explain it to its neighboring states before officially declaring it, Seoul officials said Tuesday.

Since Beijing unilaterally drew an Air Defense Identification Zone in the East China Sea last week that overlaps with those of South Korea and Japan, Seoul has been pushing to expand its zone to protect its territorial airspace.

“Within this week, the government will hold a national security policy coordination meeting to finalize its decision on the expansion of the zone and make an announcement,” a Seoul official told reporters.

The expansion, however, would not be unilaterally declared, another official said.

“When we finalize our decision, we will actively explain our position to the U.S., China and Japan. As a responsible member of the international community, our government will not (declare the expansion) in a unilateral fashion,” the official said, declining to be named.

Seoul is considering incorporating the country’s southernmost island of Marado and Hongdo, an uninhabited island south of Geojedo, in its southern air defense zone. The two islands are included in Japan’s air defense zone, but Seoul said it sees no problem in exercising its territorial right in the airspace over the islands.

Set up in 1951 by the U.S. Air Force to block communist air forces during the Korean War, South Korea’s air defense zone does not cover some of its remote territorial spots.

Seoul is also considering expanding its air zone to include Ieodo, which Beijing’s new air defense zone now covers.

South Korea is expected to explain its planned expansion to U.S. Vice President Joe Biden, who will arrive here on Thursday after visiting Japan and China on his Asia tour that began on Monday.

Seoul is already in early consultation with Washington over the controversy sparked by Beijing’s unilateral air demarcation.

Ahn Ho-young, Seoul’s ambassador to Washington, told reporters the allies have exchanged views on China‘s move from the beginning. But he refused to comment on the issue of Seoul’s expansion of its air zone.

Some observers say the U.S. might not welcome South Korea’s expanded air zone as it could weaken its rationale against China’s unilateral move to alter the regional status quo.

By Song Sang-ho (sshluck@heraldcorp.com)